1. Field of the Invention
This invention relates to a an optical lens that acts on each beam of light emitted from a light emitting element comprising an array of a plurality of light emitting components, and more particularly relates to an optical lens with which each beam of light is collimated, converged, and changed their optical path.
2. Related Background Art
An optical lens collimates (makes parallel) the light emitted from a semiconductor laser element as a light emitting element, and focuses the light onto a microscopic spot on a light receiving component such as an optical fiber. The most common configuration for a semiconductor laser element is that of a semiconductor laser array in which a plurality of light emitting components are arranged in a row, in which case the optical lens is also in the form of an array in order to collimate each beam of the incident light from the light emitting components one by one. Japanese Laid-Open Patent Application H7-98402 discloses an optical path converter in which a plurality of cylindrical lenses are disposed in a row. International Laid-Open Patent Application WO99/57791 and European Laid-Open Patent Application EP1006382A1 disclose an optical lens for semiconductor laser optical lens in which a plurality of cylindrical lenses are formed integrally. The cylindrical lenses used in the above optical path converter and optical lenses individually collimate the beams of light emitted from the light emitting components of the semiconductor laser array.
However, the following problems were encountered with these conventional optical lenses.
(1) With the optical path converter disclosed in Japanese Laid-Open Patent Application H7-98402, it was exceedingly difficult to dispose the cylindrical lenses in the form of an array such that they corresponded in pairs with the light emitting components of the semiconductor laser element in order to collimate the beams of incident light.
(2) With the optical lenses disclosed in International Laid-Open Patent Application WO99/57791 and European Laid-Open Patent Application EP1006382A1, the problem in (1) above did not occur because the lens was formed integrally, but because the bumps and crevices resulting from the cylindrical lenses were exposed on the outside, dust tended to accumulate there, and this dust became a shadow which affected the light emission performance.
In view of this, it is an object of the present invention to provide an optical lens which can be simply disposed at the location where it can act on the light emitted from the light emitting components of the light emitting element in which a plurality of light emitting components are arranged.
It is a further object of the present invention to provide an optical lens in which the bumpy portions are not exposed and therefore do not gather dust.
In order to achieve the stated object, the present invention is an optical lens which acts on the beams of light emitted from a semiconductor laser element comprising an array of a plurality of light emitting components, and then emits the light, comprising two first optical member arrays having a plurality of columnar optical members including first optical action components in the side surface of the columnar optical member that have a curved surface on either the incident light side or the emitted light side and that act on the light emitted from the light emitting components, the columnar optical members being disposed in parallel and in the same plane, and a second optical member that is columnar in shape and made of a transparent material, and inside of which the two first optical member arrays are embedded in parallel in the columnar axial direction thereof, wherein the columnar axial direction of the columnar optical members is inclined by xcex1xc2x0 with respect to the direction in which the light emitting components are arranged in the semiconductor laser element, the material of which the columnar optical members are made has a refractive index that is different from that of the transparent material of the second optical member and each of the columnar optical members has two end portions both of which are exposed from the second optical member.
With this optical lens, because the first optical member arrays that act on the incident light from the light emitting element is integrally embedded in the second optical member, it is simple to dispose them at the locations where they can act on the beams of incident light.
Also, because the bumps and crevices resulting from the curved surfaces of the columnar optical members formed when the columnar optical members are arranged are covered by the second optical member and not exposed to the outside, dust will not accumulate in these portions.
Furthermore, strength is improved because the first optical member arrays are reinforced by the second optical member.
Also, since the columnar optical members are disposed at an angle of xcex1xc2x0, each beam of incident light is emitted such that the light has been rotated by 2xcex1xc2x0 with the optical axis of the incident light being the center axis by the two first optical action components.
Furthermore, in case that the optical lens of the present invention is opposed to the semiconductor laser element, since the end portions of the columnar optical members are exposed, it is easy to position the first optical action components such that each of them is opposed to each of the light emitting components of the semiconductor laser element and possible to extend two end portions of each of the columnar optical members to the surfaces of the second optical member.
The phrase xe2x80x9cact on lightxe2x80x9d as used herein means emitting incident divergent light after first reducing its divergence angle, or converting the optical path.
It is preferable if the material of which the columnar optical members are made has a coefficient of thermal expansion that is higher than that of the transparent material of the second optical member. It the optical lens is manufactured by covering a material with a high coefficient of thermal expansion with a material with a low coefficient, the resulting caulking effect will make the structure stronger and more resistant to cracking.
It is also preferable if the material of which the columnar optical members are made has a yield point that is higher than that of the transparent material of the second optical member. The difference in yield point can be utilized to manufacture an optical lens of the type in which embedding is achieved by drawing.
The second optical member may include a second optical action component that forms a curved surface on either the incident light side or the emitted light side of the second optical member, and acts in the Y-axial direction on the light emitted from the light emitting components. If so, the second optical member will be able to act in the Y-axial direction on either the light incident on the optical lens or the light emitted from the optical lens. xe2x80x9cX-axial directionxe2x80x9d herein refers to the direction in which the light emitting components are arranged in the light emitting element, while xe2x80x9cY-axial directionxe2x80x9d refers to the direction perpendicular to the X-axial direction and the optical axis.
The present invention is also optical lenses arranged in two parallel rows, these optical lenses each being an optical lens which acts on the light emitted from a semiconductor laser element comprising an array of a plurality of light emitting components, and then emits the light, comprising a first optical member array having a plurality of columnar optical members including first optical action components in the side surface of the columnar optical member that have a curved surface on either the incident light side or the emitted light side and that act on the light emitted from the light emitting components, the columnar optical members being disposed in parallel and in the same plane, and a second optical member that is columnar in shape and made of a transparent material, and inside of which the first optical member array is embedded in the columnar axial direction thereof, wherein the columnar axial direction of the columnar optical members is inclined by xcex1xc2x0 with respect to the direction in which the light emitting components are arranged in the semiconductor laser element, and the material of which the columnar optical members are made has a refractive index that is different from that of the transparent material of the second optical member.
Because the optical lens is divided in two, its action on the incident light can be adjusted through positional adjustment.
The second optical member of the optical lens of either of the two rows of optical lenses arranged in parallel may include a second optical action component that forms a curved surface on either the incident light side or the emitted light side of the second optical member, and acts in the Y-axial direction on the light emitted from the light emitting components. If so, the second optical member will be able to act in the Y-axial direction on either the light incident on the optical lens or the light emitted from the optical lens.
The columnar optical members may be cylindrical optical members, for example. This results in more effective optical path conversion.
The columnar optical members may also be semi-cylindrical optical members, for example. This again results in more effective optical path conversion. xe2x80x9cSemi-cylindricalxe2x80x9d as used herein refers to a columnar shape, one side of which is a flat surface and the other side of which has a convex curved surface. The curved surface may be aspherical. A pair of another side surfaces each consisting of a flat surface may be further provided between the convex curved surface and the flat surface.
The present invention is also an optical lens which acts on the light emitted from a semiconductor laser element comprising an array of a plurality of light emitting components, and then emits the light, comprising a first optical member array having a plurality of columnar optical members including first optical action components in the side surface of the columnar optical member that have a curved surface on both the incident light side and the emitted light side and that act on the light emitted from the light emitting element, the columnar optical members being disposed in parallel and in the same plane, and a second optical member that is columnar in shape and made of a transparent material, and inside of which the first optical member array is embedded in the columnar axial direction thereof, wherein the columnar axial direction of the columnar optical members is inclined by xcex1xc2x0 with respect to the direction in which the light emitting components are arranged in the semiconductor laser element, and the material of which the columnar optical members are made has a refractive index that is different from that of the transparent material of the second optical member. Because curved surfaces are formed on the incident light and emitted light sides of the first optical action components of the columnar optical members, and the columnar optical members are disposed at an angle of xcex1xc2x0, each beam of the incident light is emitted such that the light has been rotated by 2xcex1xc2x0 with the optical axis of the incident light being the center axis by one of the first optical member arrays.
The curved surface of the first optical action component may be a convex curved surface, and the material of which the columnar optical members are made may have a refractive index that is higher than that of the transparent material of the second optical member,
The curved surface of the first optical action component may be a concave curved surface, and the material of which the columnar optical members are made may have a refractive index that is lower than that of the transparent material of the second optical member.
It is preferable if the columnar axial direction of the columnar optical members is inclined by 45xc2x0 with respect to the direction in which the light emitting components are arranged in the semiconductor laser element. Because the columnar optical members are disposed at an angle of 45xc2x0, the incident light is emitted such that the light has been rotated by 90xc2x0 with the optical axis of the incident light being the center axis by the two first optical action components, so the X-axial direction and the Y-axial direction are switched.
The present invention is also an optical lens comprising one of the above-mentioned optical lenses and a parallel optical lens that is disposed along with the above-mentioned optical lens and includes a third optical action component that acts in the Y-axial direction on the light emitted from the light emitting components. Because the parallel optical lens including the third optical action component is separately provided, disposition at the desired location is possible.
The present invention is also an optical system comprising a light emitting element consisting of an array of a plurality of light emitting components, one of the above-mentioned optical lenses that acts on the light emitted from the light emitting element, and a light receiver comprising one or an array of a plurality of light receiving components that receive the light emitted from the optical lens. This realizes an optical system comprising an optical lens whose disposition is simple and light emission performance is excellent, and which can emit the incident light such that it has been rotated by 2xcex1xc2x0 with the optical axis of the incident light being the center axis.
The present invention is also an optical lens, which acts on the light emitted from a semiconductor laser element comprising an array of a plurality of light emitting components, and then emits the light, comprising two first optical members each having a plurality of columnar optical portions including first optical action components in the side surface of the columnar optical portion that have a curved surface on either the incident light side or the emitted light side and that act on the light emitted from the light emitting components, the columnar optical portions being disposed in parallel and in the same plane and a second optical member that is columnar in shape and made of a transparent material, and inside of which the two first optical members are embedded in parallel in the columnar axial direction thereof, wherein the columnar axial direction of the columnar optical portions is inclined by xcex1xc2x0 with respect to the direction in which the light emitting components are arrayed in the semiconductor laser element, the material of which the first optical members are made has a refractive index that is different from that of the transparent material of the second optical member, and each of the first optical members has two end portions both of which are exposed from the second optical member.
The present invention is also an optical lens comprising two first optical member arrays each having a plurality of columnar optical members including first optical action components in the side surface of the columnar optical member that have a curved surface that acts on the incident light, the columnar optical members being disposed along a predetermined direction and the extending directions of which being disposed in parallel each other, and a second optical member that is made of a transparent material and inside of which the two first optical member arrays are embedded in parallel, wherein the extending direction of the columnar optical members is inclined by xcex1xc2x0 with respect to the predetermined direction along which a plurality of the columnar optical members are disposed, the material of which the columnar optical members are made has a refractive index that is different from that of the transparent material of the second optical member, and each of the columnar optical members has two end portions both of which are exposed from the second optical member.
The present invention is also an optical lens comprising two first optical members each having a plurality of columnar optical portions including first optical action components in the side surface of the columnar optical portion that have a curved surface that acts on the incident light, the columnar optical portions being disposed along a predetermined direction and the extending directions of which being disposed in parallel each other, and a second optical member that is made of a transparent material and inside of which the two first optical members are embedded in parallel, wherein the extending direction of the columnar optical portions is inclined by xcex1xc2x0 with respect to the predetermined direction along which a plurality of the columnar optical portions are disposed, the material of which the first optical members are made has a refractive index that is different from that of the transparent material of the second optical member, and each of the first optical members has two end portions both of which are exposed from the second optical member.